Evaporating apparatus having multiple evaporation.



W RUSIEGKI. I EVAPORATINGAPPARATUS HAVING MULTIPLE EVAPORATION.

APPLIOATION FILED APR.14, 1911.

Patented Mar. 26, 1912.

3 SHEETS-SHEET 1.

COLUMBIA PLANDGRAPH co.. WASHINGTON. D c.

W. RUSIEGKL EVAPOBATING APPARATUS HAVING MULTIPLE EVAPORATION.

. APPLICATION FILED APR. 14, 1911. 1,021,486. Patented Mar. 26, 1912.

3 SHEETS-SHEET 2.

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W. RUSIEGKI. EVAPORATING APPARATUS HAVING. MULTIPLE EVAPORATION.

AP'PLIOA-TIQNIFILED APR.14, 1911.

3 SHEETS-"SHEET 3.

WITNESSES. [NVEN'T'O'HI 6 Arron/van.

COLUMBIA PLANOGRAPH (IO-,WASHINGTON. D. C.

Patented Max 26, 1912. V

UNITED STATES PATENT OFFICE.

WAGLAW RUSIECKI, 0E RAKITNAJA, RUSSIA.

EVAPORATING APPARATUS HAVING- MULTIPLE EVAPORATION.

' the other chambers obtain their heat for evaporation from the steam orvapors formed in the first chamber. In order to obtain favorable andrapid evaporation, suction of the steam or partial evacuation in thechambers is employed in the known manner.

A primary object of my invention is to increase the output andefficiency of the evaporation process, which end I attain by arrangingand constructing the heating batteries in an improved manner.

One illustrative embodiment of my invention is represented by way ofexample in the accompanying drawings, wherein Figure 1 is a plan of anevaporating apparatus comprising four elements, Fig. 2 a verticallongitudinal section on the line AB in Fig. 1, Fig. 3 a section on thestep-shaped line G-D-EFG KL in Fig. 2, Fig. 4 a side elevation and Fig.5 a front elevation according to Fig. 4 as seen from the left.

Similar letters of reference indicate corresponding parts throughout theseveral figures of the drawings.

Referring to the drawing, each element of my improved evaporatingapparatus is an ordinary horizontal evaporator of box shape, in whichthe tubes b k iv, h forming the heating surface are not arrangedlongitudinally, but transversely. The first, or lowermost element, intowhich the liquid to be boiled enters through the valved pipe al has onits side a steam admission chamber M to which the steam for heating issupplied through one or more supply pipes a, in order to be sucked awayby a pump or the like as condensed. water by way of the branchpipe 6after passing through the Specification of Letters Patent.

air and the like.

Patented Mar. 26, 1912.

Application filed April 14, 1911. Serial No. 621,098.

heating tubes and out of the chamber N The branch pipe 0 is for removinggases,

the elements are connected one with another in such a manner that thesteam chamber of the preceding element plays the part of a steamadmission chamber for each of the following elements. In this manner thesteam chamber of the first element serves as steam admission chamber forthe second, and so on. The second, third, fourth and any other elementsare provided with the chambers N N N having outlet-pipes b 6 I2 and c c0 for conducting away the water and gases which are removed in the knownmanner by means of automatic devices or pumps.

The level of the liquid, 6. g. the level of the cane-juice insugar-mills, must be lower in the lowermost element than the lowermosttier-of heating tubes in the next following element, and so on so thatthe foam of the juice and the particles of spray from one element cannotthe following.

The valved branches d d (5 merely serve for conducting the juice fromone element to the next following elements, in connection with thebranch-pipes c c 6 The juice is sucked successively through the pipesand valved branchesv e (1 e d and 6 d from one element into another. Theinspissated juice is removed through the branch-pipe c of the uppermostchamber None of the other ele-' 'ments has a steam admission chamber,but

pass into the tubes of by means of a pump. In order to be able toregulate both the supply of the juice and its passage from one elementinto the others special valves are provided. The branch 0 is forconducting the vapor of the juice in the uppermost element to thecondenser.

P P andP designate inclined baffleplates for preventing the juice frompassing from one element into the small tubes in the next. As will beunderstood from Fig. 2, the bafiie-plates areattached to onelongitudinal wall and to the two end'walls. The free spaces or gaps It RR between the top edges of the battle-plates and the other longitudinalwall of the elements serve for conducting the vapors formed in theseelements into the small tubes of the following elements.

Q Q Q Q, designate manholes while S designate peepholes.

The small tubes forming the heating surfaces may either be beaded intothe walls of the chambers or packed therein with the aid of india-rubberrings.

In order clearly to explain the mode of operation of an evaporatingplant arranged in the aforesaid manner, I will assume that the steam ofthe first element is not to be employed for any other purpose except forevaporation work in the other elements. Further, I will assume thatchemically pure water is evaporated which forms no sediment on the smalltubes, that, for the heating, steam from the engines is used at apressure of about three atmospheres, and that the vapors pass out of theuppermost element into the condenser and into an airpump which maintainsin said uppermost element a constant, rarefied atmosphere of 60 ems.column of water. Under these conditions the absolute pressure of theexhaust steam equals 1.5 atmospheres and the absolute pressure in theair space of the fourth element will be 0.2 atmosphere.

When all the elements have an equal area, the pressure in the firstelement will amount to 1.17 5 atmos, that in the second element willamount to 0.850 atmos, that in the third element will amount to 0.525atmos, and in the fourth element will amount to 0.200 atmos.i. 6., thedifference of pressure in two adjacent elements is 0.325 atmos.:3.8 m.of a column of water. Assuming that the specific weight of the liquid inthe third element is 1.3., the column of this liquid which is to balancea column of water 1.3 m. high mustbe 3.313 254 111. It follows that witha difierence of 2 m. in the levels of the liquid in the third and fourthreceptacles, the liquid can be unimpededly sucked from one element intoanother. When the difference in pressure between each preceding andfollowing element is equal, the difference in temperature will also beequal and will be approximately 1 1 C. Now when the difference intemperature between the elements is equal and the heating surface thesame and made of the same material, and when the heating tubes are ofthe same diameter, it is generally assumed that the capability ofperformance of the heating elements is the same always supposing thatchemically pure water is evaporated in all the chambers Theconstructions of all customary evaporators known heretofore is based onthis principle. In practice it has been found, however, that the firstelements have a much greater capability of performance than the last.Experiments and consideration have shown that the cause of the reductionof the capability of performance of the following elements is that thevolume of steam increases with the diminution of the pressure.

According to Zeuners table 1 kg. of steam has at a pressure of 1.5atmos. a volume of 1.1268 cub. m. and, consequently, when the pressurein the 1st element is 1.17 5 atm. a volume of 1&197 cub. in. when thepressure in the 2nd element is 0.350 atm. a volume of 1.9295 cub. m. andwhen the pressure in the 3rd element is 0.525 atm. a volume of 3.0465.

As all evaporating apparatuses have heretofore been so constructed thatin all the elements the total of the sections of the tubes through whichthe steam passes is almost equal, it follows that with an assumed velocity in the first element of 20 meters per see, the velocity in thesecond element must be 25 m., in the third 35 m., and in the fourth 60m. In other words, in spite of the diminution of pressure the velocitymust rise, but this, however, is contrary to law. In fact, inapparatuses known heretofore no increases in velocity took place, forwhich reason the steam in the last element could not flow over theentire surface, whereby, again, a considerable portion of the heatingsurface remained unutilized and the evaporation did not correspond tothe heating area. Theoretical considerations show that, when thevelocity of the steam in the tubes of the first element is 20 1n. persecond, for the purpose of most advantageously giving up its heat, thisvelocity at the low pressure must be less than 20 m. in the followingelements and in no case greater. This conclusion is based on thefollowing considerations: Supposing that a long pipe is immersed intowater of constant temperature and steam of any desired pressure isadmitted into one end of the pipe, as the distance from the inletincreases the temperature of the steam will gradually fall until it isequal to the temperature of the water. Calculations show that with asteam pressure of 1.5 atmos, a copper tube 20 mm. in diameter, and atemperature of the water of 20 C., the temperature of the steam at adistance of 25 m. from the inlet is equal to the temperature of thewater of 20 C. Consequently at this point the delivery of heat equalszero, whereas the delivery of heat at the inlet is (11220) 22, when 112is the temperature of the steam, 20 the temperature of the water and 22the coefficient of the delivery of heat. The diminution of thecapability of delivering heat takes place uniformly and amounts permeter run to (112-20) 22: 25:91 calories. In this manner the 1st meterrun transmits 2025 calories, the 10th:2025(81.10):1215, the20th:2025(81.20):405 and the 25th: 2025(81.25):0. From this it followsthat the average amount of heat delivered by a tube 25 m. long is 1012calories,

C by one 20 meters long.

and lastly by one 10 meters long:

2 1620 calories.

the elements, and for this purpose the total section of all the heatingtubes of the individual elements must be in such a relation one toanother as the volumes of their vapors, in other words these sectionsmust be inversely proportional to the steam pressures in the individualelements. heating surfaces in all the elements are equal and if the sameconsist of small tubes of equal diameter, it is clear that for observingthis rule the number of tubes in each following element must be greaterthan in the preceding one, whereas their length must be less. But as thecapacity of the tubes increases relatively to their shortness, itfollows that in an evaporating plant based on the aforesaid principleall the elements will have an equal capacity, and the capacity of theentire plant must be greater as compared with that of plants knownheretofore. The plant in the illustrative embodiment constructedaccording to my new principle has heating surfaces of the followingdimensions: 1st element: length of tube 3 m., number 112 pieces; 2ndelement: length of tube 2.5 m., number 140 pieces; 3rd element: lengthof tube 1.75 m., number 196 pieces; 4th element: length of tube 1.25 m.,number 301 pieces. As men tioned above, these dimensions only relate toan evaporating plant in which the steam in the first chamber only isemployed in the plant and in which chemically purewater is used. If,instead of water, cane-juice or another liquid is to be boiled, the areaof each following element must of course be rather largerthan that ofthe preceding. This enlargement must correspond to the coefli- If the.

cients of the diminution of the power of conducting heat, which aredeterminable in practice in each case, in consequence of theinspissation of the juice and the sediment in the tubes. If steam forheating other apparatus is withdrawn from one of the ele ments, e.g.,.tl1e third, the area of this ele ment, and also the areas of all thepreceding elements mustbe increased by a corresponding number of tubes.

I claim r 1. In an evaporating apparatus of the character described, thecombination, with a series of box-like horizontal elements arrangedadjacent to each other and stepshaped one above theother, of a system ofrectilinear heating tubes arranged transversely of the same andcommunicating with the preceding chamber, liquid supply pipes connectingeach preceding element with the next following element, a liquidsupply-pipe for the lowermost element, means for supplying steam to thetransverse heating tubes of the lowermost element, and means forconducting the steam away-from the heating tubes of all the elements.

2. In an evaporating apparatus of the character described, thecombination with a series of box-like, horizontal elements arrangedadjacent to but step-shaped one above the other, of transverse heatingtubes arranged in each element and communicating with the next precedingelement, liquid supply pipes connecting each preceding element with thenext following element, a liquid supply-pipe for the lowermost element,means for supplying steam to the transverse heating tubes of, thelowermost element, and

means for conducting the steam away from the heating tubes of all theelements, the total cross-section area of the tubes in each elementbeing greater in each following element than in the preceding element.

3. In an evaporating apparatus of the character described, thecombination with a series of box-like, horizontal elements, ar rangedadjacent to but step-shaped one above the other, of a plurality ofrectilinear heating tubes arranged transversely in said elements andcommunicating at one end with the next preceding element, liquid supplypipes connecting each preceding chamber with the next following chamber,a liquid supply-pipe for the lowermost element, means for supplyingsteam to the transverse heating tubes of the lowermost element, andmeans for conducting the steam away from the heating tubes of all theelements, the length of the tubes in each element being less in eachfollowing element than in the preceding one.-

'4. In an evaporating apparatus of the character described, thecombination, with a series of box-like, horizontal elements arrangedadjacent to and step-shaped one above the other, of a plurality ofrectilinear heating tubes arranged transversely in said elements andopening at one end into the preceding chamber, valved liquidsupply-pipes connecting each preceding chamber with the next followingchamber, a liquid supply pipe for the lowermost element, means forsupplying steam to the heating tubes of the lowermost element, and meansfor conduct ing the steam away from the heating tubes of all theelements, the level of the liquid in each following element being higherthan that in each preceding element but below the lowermost tier ofheating tubes in the next element.

5. In an evaporating apparatus of the character described, thecombination, with a series of box-like, horizontal elements arrangedadjacent to and stepshaped one above the other, of a plurality ofrectilinear heating tubes arranged transversely in said elements andopening at one end into the preone element to the heating tubes of thenext following one.

In testimony, that I claim the foregoing as my invention, I have signedmy name in presence of two subscribing witnesses.

. WACLAXV RUSIEGKI.

WVitnesses:

GYPRIAN KossoBUDsKI, AUG. MIGHIs.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. 0.

